Research On The Features Of DNA Methylation In The Proce Ss Of Growth And Development In Bamboo

In order to research the epigentiecs in bamboo development stages and micropagation, the technique of MSAP and HPLC was employed to detect DNA methylation in leaves of different chronological ages of Phyllostachys heterocycla var. pubescens,diffenent development stages of Bambusa. multiplex and Ph.vivax f.aureocaulis from diffenent areas. The results are as follows:1 DNA methylation ratio of Phyllostachys heterocycla var. pubescens increased with chronological ages.Experiment material is Moso bamboo (Phyllostachys heterocycla var. pubescens) leaves with 3 various chronological ages (5, 31, and >60 years after seed germination). During the procedure of genome DNA extration and MSAP analysis, total 35 pairs of MSAP primers were amplyfied. DNA methylation and demethylation patterns were observed in the genomic DNA, and the variable sites of methylation (52.3%) were more than those of demethylation (10.3%). Thereafter, methylation sites increased with the rising ages in the genomes. Moreover the result of variance analysis for methylation ratio indicated that no significant (P=0.307 > 0.05) difference among individuals with the same ages, while significant (P < 0.001) difference exsited among different chronological ages.2 Fitted relationship between genome DNA methylation ratio and chronological age from Moso bamboo, based on MSAP technology of six selected primer combinations.Through ANOVA it showed that 6 pairs (E3/HM2, E3/HM6, E3/HM7, E4/HM5, E4/HM6and E5/HM5) of primers had obvious influence on DNA methylation for ones with different chronological ages and could be used for further research. The futher analysis using Main points of law indicate that there is a aggregative indicator which can show the gross information content of DNA methylation level of the Moso bamboo, and the expression is Y = 0.173 X1+0.172 X2+0.172X3+0.178X4+0.176X5+0.180X6.Then, we tested more ages's Moso bamboo,consist of 2 years, 6years, 13 years, 18 years, 31 years, and >60 years. Take advantage of SPSS conduct an curve fitting in the rate of methylation of different physiolgical age and show a incremental rendering.The relatons between physical age and DAN methylation level was refined. That is: Z=0.542y2-0.003y+17.999, R2=0.970. This result showed an important practical significance for the judgement of biological age from Moso bamboo.3 The DNA methylation rate in flowering plants is lower significantly than non-flowering of Bambusa multiplex.HPLC was used to sdudy the genomic DNA methylation in the flowering process of Bambusa multiplex. Before flowering, the methylation of genomic DNA was no significant difference in development stages but showed an irregular fluctuations. But, there is an obvious difference in the DNA mehtylation of flowering and non-flowering from Bambusa plants. Meanwhile, detect the DNA methylation on flowering and non-flowering bamboos based on MSAP. It can be concluded that DNA methylation and demethylation patterns were observed in the genomic DNA, and the variable sites of demethylation (22.28%) were more than methylation those of (1.98%). Thereafter, eventually leading to flowering plants genome methylation was significantly lower than flowering plants.In this study, Detection of DNA methylation based on HPLC ande MSAP and the results were consistent. Moreover, MSAP was only assess methylation in total DNA at CCGG sites in the process of flowering. The results clearly demonstrate that HPLC technique is highly than the detection of the value of MSAP.4,With the lower latitudes, DNA methylation level of Ph.vivax f.aureocaulis which were from the same clonal origin and located in different habitats gradually reduced.The experimental materials were Ph.vivax f.aureocaulis, which were located in Jiangsu, Beijing, Zhejiang, Jiangxi, Sichuan, Guangdong. Ph.vivax f.aureocaulis of six regions were from Anji. Analysis of genetic diversity was studied in AFLP. The results showed that genomic DNA sequence of Ph.vivax f.aureocaulis which were located in different habitats and from the same clonal origin have no difference. MSAP detection revealed that the total methylation rate and full rate of methylation were 33.62%,33.19%,31.19%,30.93%,29.50%,28.78%å'Œ19.57%,19.27%,18.60%,18.01%,16.32%,14.49%. The results showed that with the lower latitudes, DNA methylation level gradually reduced. The six pairs of primers closing with age of Phyllostachys heterocycla var. pubescens were applied in MASP test of Ph.vivax f.aureocaulis. The clear picture revealed that Ph.vivax f.aureocaulis are basically the same MSAP amplified bands, there was no difference, this suggested that based on selected pairs of primers, on the same clonal origin of Ph.vivax f.aureocaulis which were located in the different habitat terms, the genomic DNA sequence did not occur methylation mutation. From another point of view ,this is also verified, the selected six pairs of primer have the feasibility in detecting physiological age of Moso bamboo, and in different bamboo species may exist in versatility.